Flash application web domains. Adobe Flash applications may require access to the properties of images delivered with fmt=swf or fmt=swf3.
The swf must grant access explicitly by registering the name of application domains it trusts.
String containing a comma-separated list of web domain names. If empty, applications must be served from the same domain as Image Rendering to be able to access the properties of images in swf-formatted responses.
default::TrustedDomains if not present.